When trees are lost due to deforestation, the result can be a drier climate and desertification or the transformation of the once fertile land to desert. Learn how deforestation and desertification can lead to a decline in biological diversity.
Natural Environments
Imagine that you are out on a camping trip deep within the forest. During the day, you enjoy watching the animals and birds as they play among the trees and plants. Then, at night, you climb into your tent and fall asleep listening to the crickets, bullfrogs and other creatures of the night. But, as morning breaks, you step out of your tent to find that all of the plants and animals have disappeared and, in their place, is dry and barren land.
Okay, this is a bit extreme, and this drastic of an environmental shift could not happen overnight. However, with mismanagement of woodland and natural disasters, lush forests can be negatively impacted and can even turn into deserts over time. In this lesson, we will take a look at how these changes take place and how they impact the biological diversity of the ecosystems.
Deforestation
Deforestation is the term that describes the cutting down or clearing of trees from a wooded area. There are a number of reasons woodlands or forests are cut down. In some cases, the trees themselves are the desired resource. Trees have been a source of fuel for many generations and continue to be used in this way today. They are also turned into timber for use in building and carpentry, as well as used in the production of paper products.
In other cases, trees are cleared because they are in the way of progress. Forests may be cleared to make room for farmland or for grazing land for cattle, or they may be removed to make room for new houses, neighborhoods or expanding cities. Some deforestation is not intentional and can result due to natural causes, such as wildfires.
Regardless of the cause, deforestation can be detrimental to the environment. A forest acts as a carbon sink because it absorbs carbon dioxide from the atmosphere during the process of photosynthesis. When trees are destroyed, they release their stored carbon dioxide back into the atmosphere, which contributes to the greenhouse effect. The greenhouse effect is the phenomenon whereby atmospheric gases, like carbon dioxide, trap the sun's heat, causing the earth's surface to warm.
The harmful effects of deforestation can also be seen on land. Without trees to protect soil and hold it in place, soil erosion, or the washing away of soil, can occur during periods of rain. Trees also play a pivotal role in the water cycle, which is the constant movement of water between the earth and the atmosphere.
Tree roots absorb water from the ground and return water vapor back to the atmosphere. If trees are removed and can no longer contribute to the water cycle, the previously forested land can transform into a much drier climate. This dry environment can spread due to a decrease in atmospheric water vapor and results in a decline in precipitation levels in the area.
Desertification
These factors all combine to create a warmer and drier climate and may result in desertification, which is the transformation of once fertile land into desert. Deforestation is not the only cause of desertification. Land can turn dry and barren due to drought, shifts in the climate or aggressive agricultural or grazing practices.
All of these causes, along with deforestation, lead to the loss of vegetation in the area. Without the vegetation, soil erosion accelerates and water does not easily absorb into the ground. The soil becomes dry and deplete of moisture and groundwater reserves go unfilled. The soil is left unfertile and barren with nothing to do but bake in the hot sun.
Biodiversity
It's easy to see that deforestation and desertification have many detrimental effects on the environment, but one of the most devastating impacts is on the loss of biodiversity. Biodiversity, or biological diversity, is the variability of life forms within a given ecosystem. This is an easy term to recall if you remember that the word 'bio' refers to 'life' and the word 'diversity' refers to 'variety.' So, the term 'biodiversity' literally means a variety of life forms.
Forests support biodiversity by providing natural habitats for various plants and animals. Forests, and especially tropical rainforests, provide some of the greatest areas of biodiversity on the planet, and a decline in these environments means a decline in biodiversity.
Biodiversity is important for the proper functioning of all types of ecosystems and plays a role in recycling nutrients and providing healthy soil. A biologically diverse ecosystem is a stable ecological community, but if this diversity is compromised, by such things as deforestation, the natural balance of the ecosystem is disrupted. This leads to the loss of habitats for many lesser species.
It also destroys medicinal plants that have been used for hundreds of years to heal human ailments. The tropical rainforests are still the origin of medications used today for the treatment of cancer and other diseases. If deforestation continues at its current pace, the loss of biodiversity could compromise the existence of medicinal plants used for therapeutic purposes.
